<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>

    <style>
        div {
            width: 100px;
            height: 100px;border: 1px solid #000;
        }
        .box {
            float: left;
        }
    </style>
</head>
<body>

    <div class="box"></div>
    <div class="box"></div>
    <div class="box"></div>
    <div></div>
    <div></div>
    
</body>
</html>